Damper control mechanism



March 6, 1934. J. F. ROUGVIE DAMPER CONTROL MECHANISM Filed April 26, 1933 /r venfor James F/Fougv/ by iML W Afforney.

Patented Mar. 6, 1934 UNITED STATES PATENT OFFICE 4 Claims.

My invention relates to an improvement in mechanism for thermostatic control of the dampers of house heating furnaces, hot water heaters, and steam boilers, which use a solid fuel such as I 5 wood, coal, coke or similar substance; and the object of the invention is to provide a simple and inexpensive type of mechanism which, being of low voltage, can be easily installed by the average householder without the aidof a licensed elec- 1') trician and can be employed in rural areas which are not serviced by any power supply company.

I attain the control of the dampers on the various types of heaters by means of the mechanism illustrated in the accompanying drawing, in

which: Fig. 1 is a front elevation of the mechanism which converts electrical energy to mechanical energy and opens or closes the heater dampers under the control of the thermostat; Fig. 2 is a diagram of the electric wiring which conmeets the actuating motor of the mechanism with the thermostat and with the source of current; and Fig. 3 is an elevation which shows the manner in which the various component parts of the combination may be located in a dwelling and the way in which they may be connected with a heating boiler of conventional type. 7

Similar numerals refer to similar parts throughout the several views. r

The motor 1 is a conventional series wound motor of the commutator type, wound for either direct or alternating current, of a low voltage, such as is usually furnished by batteries of dry cells, or a voltage reducing transformer of the bell-ringing type.

The double polo double throw or reversing, switch 3 is of the conventional toggle type as is so designed as to be positive in action; that is the switch blades remain in engagement with the contacts at one end of the switch while the actuating lever 12 is carried toward the contacts at the other end of the switch by chain 11 and until a certain point in the travel of the actuating lever has been reached, at which time the blades leave the contacts with which they have been in en gagement and engage the contacts at the other end of the switch. By means of such switch the direction of the current through one motor winding may be reversed while the current through the other winding continues to flow as before, thus reversing the direction of rotation of the motor shaft.

The gear train consists of pinion gear 4 attached to the end of the motor shaft, large driven gear 5 which is firmly affixed to one end of counter shaft 6, pinion gear 7 firmly ailixed to the other end of the same counter shaft; while counter shafe 8 carries firmly afiixed to one end thereof large gear 9 and drum 10.

The chain 11 has one end firmly affixed to drum and theother end aifixed to the lever 16 on the heater which is in turn connected to the dampers k n on the heating boiler.

The actuating lever 12 of the switch 3 is connected to chain 11 at a suitable distance from the drum, and weight 13 is afiixed to the actuating lever 12 to insure its dropping to the lower position when there is no tension on that portion'of the chain which connects it with the drum 10.

The gear train, motor and switch are mounted in a partitioned metal box 31 fastened to the'ceiling above the heating boiler. The thermostat 14 is mounted on the wall surface in the room whose temperature it is desired to regulate and it is connected to the motor and to the switch by means ofthe wiring 15. i

The damper operating lever weight 16 is so adjusted that, when the thermostat is in the warmer position, that is, in a position where the heating plant is warming the air surrounding the thermostat, the smoke flue damper 17 is closed, the ash pit damper 18 is open, and the electric circuit between the thermostatbar 14 and contact 19 is closed. Under these conditions the switch actuating lever 12 is in the lower position and the two blades of switch 3 are in contact with studs 20 and 21; the circuit is open and no current is flowing through the motor 1.

As the temperature of the air surrounding the thermostat rises to a degree corresponding to the upper limit setting of the thermostatthe-mo'ving bar 14" of the thermostat will close contact 22 and current will flow through from the source of current 2 (located in metal box 32 in Fig. 3) to switch terminal 23, thence through a switch blade in switch 3 to switch terminal 21, thence through the closed contact 22 of the thermostat 14, thence through the armature winding of the motorin the direction of the arrow 24 in Fig. 2, thence along a switch blade in switch 3 from contact 20 to contact 25, thence through the field winding of motor 1 in the direction of arrow 26 in Fig. 2, thence back to the current source.

The current flowing in this way through the armature and field coils of motor 1 causes the motor armature to rotate in a clockwise direction as indicated by the arrow 2'7 in Fig. 1. Pinion 4 on the motor shaft also rotates in a clock wise direction and being meshed with the large gear 5 causes the latter to rotate in a counterclockwise direction at reduced speed. Pinion '2' in Fig. 1 being fixed to the opposite end of shaft 6 also rotates in a counter-clockwise direction, and, as its teeth are meshed with the teeth of the large gear 9, which is fixed on shaft 8, said gear 9 is caused to rotate in a clockwise direction at a further reduced speed. 7

The drum 10, also fixed to shaft 8, is caused to rotate in a clockwise direction and windup the chain which is attached to switch actuating lever 12 and damper operating lever .16. ;These levers 12 and 16 are raised until the switch actuating lever 12 reaches its upper position at which time the switch blades attached to contacts 23 and 25 in switch 3 leave contacts 21 and 20, thereby opening the circuit and stopping the motor.

The damper in the smoke flue is now open, the damper in the ash pit door is closed, and the switch blades are in contact with terminals 28 and 29.

When the temperature of the air surrounding thermostat 14 drops to a degree corresponding to the lower limit setting of the thermostat, the moving bar of the thermostat will close the contact 19 and current will flow from the source 2 to terminal 23 of the switch, thence along a switch blade to terminal 28, thence to the armature winding of the motor 1 and through the armature winding in the direction of the arrow 30 in Fig. 2, a direction opposite to that in which current flowed when the motor was operating as indicated by the arrow 27 in Fig. 1.

From the armature winding the current flows to the moving bar of the thermostat 14, across the closed contact 19 to switch terminal 29, along a switch blade to terminal 25, thence through the field winding of motor 1 in the direction indicated by arrow 26 in Fig. 2 and back to the source of current. As the polarity of the armature winding of the motor is the reverse of what it was with respect to the polarity of the field winding, the motor armature rotates in a counterclockwise direction or a direction opposite to that indicated by arrow 27 in Fig. 1.

This counter-clockwise rotation of the motor armature causes the gear train and drum to revolve in a direction opposite to that when the motor armature rotated in a clockwise direction and the chain is partially unwound from the drum 10 in Fig. 1, thus permitting lever 12 in Fig. 1 and the lever 16 in Fig. 3 to drop to the lower position, and when the lever 12 drops sufiiciently the switch blades which are attached to terminals :23 and 25 leave contacts 28 and 29 opening the circuit and stopping the motor.

The smoke flue damper of the heating boiler is now closed and the ash pit damper open.

It is obvious that there may be substituted for the gear train shown and described any equivalent of such mechanism as, for instance, rack and pinion, worm and gear, or sprocket chain and sprocket.

It is obvious also that, where manual remote control, rather than thermostatic remote control of heater dampers is desired, there may be substituted for the thermostat a manually operated switch.

Among the advantages secured by my invention is that, when the steam pressure or the water temperature in the boiler rises above prescribed upper limits before the temperature of the atmosphere surrounding the thermostat reaches its prescribed upper limit, the conventional damper regulator on the boiler will cause the ash pitdamper 18 to close and the smoke flue damper 17 to open, retaining their respective positions until the steam pressure, or water temperature, has dropped to its prescribed upper limit, when they will respectively open and close. In this particular feature my device, as illustrated and described, supplements the pressure or temperature operated damper regulator usually found on steam or hot water boilers.

Another advantage is the small cost of the mechanism as compared with that of other devices employed for the same purpose.

I claim- 1. Thermostatic damper control mechanism comprising, in combination, a support; a reversible series wound electric motor of the commutator type mounted on the support; a gear train mounted on the support and actuated by the motor; a drum mounted on the gear train and actuated thereby alternately in clockwise and counter-clockwise directions; a chain having its upper end attached to the drum windingly thereon, its lower end free for operative engagement with the conventional damper operating lever, and being intermediate its ends attached to the actuating lever of a double pole double throw reversing switch of the conventional toggle type, positive in action, mounted on the support; a thermostat electrically connected to the switch and motor; and a source of low voltage electric current either direct or alternating.

2. Thermostatic damper control mechanism comprising, in combination, a reversible series wound electric motor of the commutator type; a gear train actuated by the motor; a drum mounted on the gear train and actuated thereby alternately in clockwise and counter-clockwise directions; a chain having its upper end attached to the drum windingly thereon, its lower end free for operative engagement with the conventional damper operating lever, and being intermediate its ends attached to the actuating lever of a double pole double throw reversing switch of the conventional toggle type, positive in action; a thermostat electrically connected to the switch and motor; and a source of low voltage electric current either direct or alternating.

3. Thermostatic damper control mechanism comprising, in combination, a support; a reversible series wound electric motor of the commutator type mounted on the support; a gear train mounted on the support and actuated by 15 the motor; a drum mounted on the gear train and actuated thereby alternately in clockwise and counter-clockwise directions; a chain having its upper end attached to the drum windingly thereon, its lower end free for operative engagement 0 with the conventional damper operating lever, and being intermediate its ends attached to the actuating lever of a double pole double throw reversing switch of the conventional toggle type, positive in action, mounted on the support; a single pole double throw switch electrically connected to the switch and motor; and a source of low voltage electric current either direct or alternating.

4. Thermostatic damper control mechanism 130 comprising, in combination, a reversible series wound electric motor of the commutator type; a gear train actuated by the motor; a drum mounted on the gear train and actuated thereby alternately in clockwise and counter-clockwise directions; a chain having its upper end attached to the drum windingly thereon, its lower end free for operative engagement with the conventional damper operating lever, and being intermediate its ends attached to the actuating lever of a double pole double throw reversing switch of the conventional toggle type, positive in action; a single pole double throw switch electrically connected to the switch and motor; and a source of low voltage electric current either direct or alter- 5 hating.

JAMES F. ROUGVIE. 

